Algorithms for Arrival Time Estimation of Partial Discharge Pulses in Cable Systems

Partial discharge (PD) detection and location in cable systems is a valuable tool for the estimation of the condition of the system. Accurate localization of the PD origin, based on arrival times, is required for the identification and assessment of the defect. This paper evaluates different time-of-arrival algorithms to determine which method yields most accurate location under different circumstances. These methods are based on trigger level, Akaike Information Criterion (AIC), energy criterion, Gabor´s signal centroid and phase in frequency domain. Several criteria are defined by which the algorithms are evaluated. These criteria include the sensitivity to the noise level, the sensitivity to the pulse shape and others. The methods are tested on a medium-voltage cable system by injecting PD pulses in a cable with a joint at a known location. Each algorithm is applied to the measured pulses and the resulting location is compared with the known location. From the result the methods using the energy criterion and the phase are preferred.